Here is a screengrab of my Toonboom set up. I've got the drawing named "bi_r_hand" selected and you can see that on the stage by the orange bounding box around the hand, on the timeline as the selected drawing is highlighted and in the library as instance 1_1 is selected of drawing 1_1.
Let's take a look at the equivalent for this in Flash. In the screen cap below I've got a Flash file open and I'm on frame 93 of an animation. The front paw symbol is selected and you can see in the Properties tab that it's called "paw" and is set to single frame and instance 2.
Let me know if you have any burning Flash or Toonboom (or hand drawn) animation questions! I'd be happy to post more tutorials in the future if people find them helpful. This one was inspired by Jay Edry.
An extra note: Particularly for TV and film productions, it is useful when using Flash to add new symbols to a file by embedding them inside master symbols set graphic and single frame. (For example with hand or face symbols.) Using symbols set to movie clip in a film production is more or less a no-no, however they are often useful for web animations. More often than not though, I use graphics whenever I can in any Flash animation. Keeping the timeline and library clean and easy to navigate are of utmost importance for the efficient animator, especially when sharing files. I currently work at a game studio and I've had to access other animator's Flash files that were animated a couple years ago. When the animators created those files, they did not dream that their files would be opened up again and reauthored or tweaked. But it's best to always assume that your work can and will be opened up by another artist at a later date.
Happy Digital Animating!